Jambo Mzee, habari?
Are you talking about Marka or Queen Alia? I only know Marka. In my ideal world I would avoid at all costs using Royal Wings as handling agents. Order your fuel good and early. On no account allow them to park you in the "Golf" area (the area towards the threshold of 24 where the cargo and foreign military aircraft park). There is no tug there so always park so that you can taxi away. Beware ice in the early mornings, there is no de-icing rig. They use a taxiway on the main apron for parking (I think it is taxiway "F" but can't be sure) beware, the tarmac is soft and if your aeroplane has a heavy footprint you could find yourself sinking into the tarmac.
Accomodation. The Marriott was very tatty (chafu sana). The Intercontinental does a pretty good deal, and that is where we have settled. Otherwise there is a Hyatt, and a Radisson. Have yet to get round to the "Rovers Return" but hear it is a good watering hole for the expat. community.
Hope that helps.